1. Field of the Invention
The present invention relates to alight control system.
2. Description of the Related Art
With enhancement of image quality of small-size image pickup devices such as mobile devices having image pickup function and micro video scopes in recent years, there are increasing needs for optical elements such as lenses, stops, and optical filters to shift from fixed focal length lenses, fixed aperture stops, filters having fixed characteristics used in the past to adjustable focus lenses, variable stops, and variable characteristic filters. Moreover, many light control systems have been developed as means for reducing the size of optical components used in small-size image pickup devices.
Japanese Patent Application Laid-open Publication No. H10-20360 discloses a light quantity control apparatus as an example of such light control systems. FIG. 5 is an exploded perspective view showing the overall construction of a conventional light quantity control apparatus.
The light quantity control apparatus shown in FIG. 5 has a printed board having a multi-layer structure and a coil having a film core made of a material having high magnetic permeability provided on the printed board. A cylindrical rotor 920 magnetized to have at least two magnetic poles is fitted to the coil part 925 having the above-described structure, and a stop blade 915 used to control the transmitted light quantity is fixedly attached to the rotor 920. The stop blade 915 is arranged between upper and lower plates 910, 911 and shifted in the gap between the upper and lower plates 910, 911 by the coil formed on the printed board.